1/500th or faster in failing light with a 580EX II

admirable

admirable

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Jim
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How do I achive this outdoors?

I have a 40D
 
Set the camera to manual and press the hi speed sync button on the flash ?
 
Tried that, subject blurred or very underexposed.
 
yep, just remember you're range will be reduced quite a bit because of the way it works though
 
Have you upped the ISO and opened the aperture sufficiently to get at least some ambient in the background or on the subject?

Also, why do you need 1/500th? Remember that the flash will freeze your subject if it is the significantly dominant light source.
 
Isn't the X-sync speed on the 40D 1/250th? This means that 1/250th is the shorted duration you can use without there being a black band at the top and/or bottom of your image where the shutter wasn't fully open when the shutter fired.

The hi speed sync thing is lots of VERY short duration pulses of flash, rather than one flash, hence not freezing the image.
 
img1856ajb9.jpg


Standard Information
Make: Canon
Model: Canon EOS 40D
Software: Adobe Photoshop CS3 Windows
ImageSize: 800x546
CreateDate: 2008:10:01 21:50:05+01:00
ModifyDate: 2008:10:01 22:32:26+01:00
DateTimeOriginal: 2008:10:01 18:17:09.01+01:00
ExposureTime: 1/320"
Aperture: F2.8
MaxAperture: F2.8
CircleOfConfusion: 0.004 mm
HyperfocalDistance: 454.88 m
ExposureProgram: Manual
ExposureBiasValue: 0
MeteringMode: Partial
Flash: On
ISO: 400
WhiteBalance: As Shot
FocalLength: 70.0 mm
FocalLength35efl: 70.0 mm (35 mm equivalent: 546.7 mm)
ColorSpace: Unknown (-1)
Contrast: +25
Saturation: 0
Sharpness: 25
 
With the 40D you can't as it's 1/250th, so If you put it up to 1/500th you'd get a black band over the image

Why do you need to shoot at 1/500th anyway? Just up the f number allowing less ambient light to freeze movement, if thats what you wanting to do
 
From the example you have shown I would say the flash is working fine and is providing a touch of fill to the subject. However, that is probably not what you want - you would like the subject better exposed relative to the background. You are also at or pushing the limit for HSS (the range for HSS is considerably less than normal flash).

At a guestimate you are approx. 12 to 15 metres from the subject. I would set the flash to manual (not Ettl) and adjust power until the range displayed on the flash is within/at the target distance. Adjust your shutter speed to get within the 1/250 sync speed. Do a test shot (get someone to stand at approx. the target distance) and adjust flash power to your taste. You can also set rear-curtain sync to ensure that any ambient exposure of your target is trailing rather than leading in the exposure.

Remember it is two exposures, your ambient and your flash. Adjust each accordingly but stay within the sync speed. Effectively set your shutter to 1/250 and adjust ISO and aperture to get the ambient correct and then adjust flash power to get your subject correct.

Hope this helps.
 
I think you really need to up the ISO. I can't see any real effect the flash is having on this subject. I suspect it may be just to far away. Looking at the Hyperfocal distance of 450 meters and at F2.8 makes the focus point about 50 or so meters . is this a fairly large crop? I think the image is just underexposed by about 1 stop so upping the ISO would help

As said previously, there is no point is setting your speed to 1/500 as the cameras sync speed is around 1/250 .
 
Chappers said:
As said previously, there is no point is setting your speed to 1/500 as the cameras sync speed is around 1/250 .
Click to expand...

That's the whole point of using high speed synch. It's allowing you to use the flash with a faster shutter speed than the standard synch speed. In things like motocross it's handy where, as in this case, you're shooting against the sky, it's easy to get a silouhette and you want to bring out detail in the subject.

These illustrate the difference at 1/320, they're not great shots, and to be honest I'm not a huge fan of the effect but it can be really effective.

ML1W3837.jpg


ML1W3838.jpg
 
Craikeybaby said:
Isn't the X-sync speed on the 40D 1/250th? This means that 1/250th is the shorted duration you can use without there being a black band at the top and/or bottom of your image where the shutter wasn't fully open when the shutter fired.

The hi speed sync thing is lots of VERY short duration pulses of flash, rather than one flash, hence not freezing the image.
Click to expand...

I think you are getting confused with the strobe function, High speed sync, syncs the the flash to faster shutter speeds as I was lead to believe.
 
The black band theory doesn't seem to affect the shots but I don't have a shot at 1/500th to look at as I binned so many in disgust! :bang:

The pic here is not a crop and I recon he's about 20-25 ft away max.

I'll be the 1st to admit my flash photography is poor but this seems very hard to grasp. Most of the pics I have taken are blurred so perhaps I'm looking at this the wrong way and should keep the shutter speed at 1/250 and adjust something else.

I have seen shots of cars/bikes taken at night with flash, eg; le mans 24hrs, so it must be possible.

Is there any way of getting an exif type data for the flash?

I'll need to look into what actually happens with high speed sync.

thanks for the pointers guys!
 
^ That is exactly the link I was looking for!
 
so basically hi speed sync is useful for fill flash on reletivley close subjects. If power is done to a third with hss then you will jsut have to take that into account.
I'm glad that someone showed me this - maybe this will help me to use the flash better!
 
33L said:
so basically hi speed sync is useful for fill flash on reletivley close subjects. If power is done to a third with hss then you will jsut have to take that into account.
I'm glad that someone showed me this - maybe this will help me to use the flash better!
Click to expand...

Well that's pretty much what oncamera flash is, you're pretty limited to fill in or bounce. It's when you take it off camera that it becomes interesting.

One thing to grasp with flash is that even on full power the burst only lasts 1/1000sec, half power is 1/2000sec etc. So if the flash is the main light source for the subject, and there isn't much ambient light, then it really doesn't matter (within reason) how long the shutter is open because the flash is only going to fire and expose your photo for a split second.

The better radio triggers allow you to shoot in hispeed sync up to 1/8000 which is a major advantage over the cheaper triggers and open up a range of possibilities when shooting sport.
 
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